7-Year-Old Polkit Flaw Lets Unprivileged Linux Users Gain Root Access
Jun 11, 2021
A seven-year-old privilege escalation vulnerability discovered in the polkit system service could be exploited by a malicious unprivileged local attacker to bypass authorization and escalate permissions to the root user. Tracked as CVE-2021-3560 (CVSS score: 7.8), the flaw affects polkit versions between 0.113 and 0.118 and was discovered by GitHub security researcher Kevin Backhouse, who said the issue was introduced in a code commit made on Nov. 9, 2013. Red Hat's Cedric Buissart noted that Debian-based distributions, based on polkit 0.105, are also vulnerable. Polkit (née PolicyKit) is a toolkit for defining and handling authorizations in Linux distributions, and is used for allowing unprivileged processes to communicate with privileged processes. "When a requesting process disconnects from dbus-daemon just before the call to polkit_system_bus_name_get_creds_sync starts, the process cannot get a unique uid and pid of the process and it c...
